User equipment (UE), such as a computer, PDA, cellular phone, smartphone, tablet PC, laptop, etc., are increasingly equipped with both a wireless local area network (WLAN), e.g. Wi-Fi, and a wireless wide area network (WWAN) cellular radio, e.g. 3G. One type of 3G radio technology is the Universal Mobile Telecommunications System (UMTS). A multi-radio UE may connect to the Internet over WLAN whenever it is available. The multi-radio UE may also switch to WWAN when performance degradation over WLAN is detected.
Compared to WiFi, 3G systems may operate under more radio resource constraints. To efficiently utilize the limited radio resources, UMTS may introduce for each UE, a radio resource control (RRC) state machine that determines radio resource usage affecting device energy consumption and user experience. Usually a UE can be in one of three states, each with different amount of allocated radio resources. The transitions between states also have significant impact on the UMTS system. Frequent state promotions (resource allocation) may lead to unacceptably long delays for the UE to acquire capability to send and receive data, as well as additional processing overheads for the radio access network and additional UE power consumption. State demotions (resource release) are controlled by inactivity timers affecting radio resource utilization and UE energy consumption.
State promotions may incur long “ramp-up” latency, also referred to as a hand-off latency, of up to 2 seconds during which tens of control messages are exchanged between a UE and the Radio Network Controller (RNC) for resource allocation (e.g., radio bearer setup and RRC connection setup). Excessive state promotions increase the management overhead at the RNC and degrade user experience, especially for short data transfers.
Therefore, it would be advantageous to have a method, system, and computer program product that addresses one or more of the issues discussed above.